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291 lines
10 KiB
291 lines
10 KiB
"use strict"; |
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Object.defineProperty(exports, "__esModule", { value: true }); |
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exports.Pool = void 0; |
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const Deferred_1 = require("./Deferred"); |
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const AggregateError_1 = require("./AggregateError"); |
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class Pool { |
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constructor(factory) { |
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this.log = false; |
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if (!factory.create) { |
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throw new Error('create function is required'); |
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} |
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if (!factory.destroy) { |
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throw new Error('destroy function is required'); |
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} |
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if (!factory.validate) { |
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throw new Error('validate function is required'); |
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} |
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if (typeof factory.min !== 'number' || |
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factory.min < 0 || |
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factory.min !== Math.round(factory.min)) { |
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throw new Error('min must be an integer >= 0'); |
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} |
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if (typeof factory.max !== 'number' || |
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factory.max <= 0 || |
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factory.max !== Math.round(factory.max)) { |
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throw new Error('max must be an integer > 0'); |
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} |
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if (factory.min > factory.max) { |
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throw new Error('max is smaller than min'); |
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} |
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if (factory.maxUses !== undefined && |
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(typeof factory.maxUses !== 'number' || factory.maxUses < 0)) { |
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throw new Error('maxUses must be an integer >= 0'); |
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} |
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this.idleTimeoutMillis = factory.idleTimeoutMillis || 30000; |
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this.acquireTimeoutMillis = factory.acquireTimeoutMillis || 30000; |
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this.reapIntervalMillis = factory.reapIntervalMillis || 1000; |
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this.maxUsesPerResource = factory.maxUses || Infinity; |
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this.log = factory.log || false; |
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this._factory = factory; |
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this._count = 0; |
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this._draining = false; |
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this._pendingAcquires = []; |
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this._inUseObjects = []; |
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this._availableObjects = []; |
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this._removeIdleScheduled = false; |
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} |
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get size() { |
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return this._count; |
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} |
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get name() { |
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return this._factory.name; |
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} |
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get available() { |
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return this._availableObjects.length; |
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} |
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get using() { |
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return this._inUseObjects.length; |
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} |
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get waiting() { |
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return this._pendingAcquires.length; |
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} |
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get maxSize() { |
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return this._factory.max; |
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} |
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get minSize() { |
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return this._factory.min; |
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} |
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_log(message, level) { |
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if (typeof this.log === 'function') { |
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this.log(message, level); |
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} |
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else if (this.log) { |
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console.log(`${level.toUpperCase()} pool ${this.name || ''} - ${message}`); |
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} |
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} |
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_removeIdle() { |
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const toRemove = []; |
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const now = Date.now(); |
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let i; |
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let available = this._availableObjects.length; |
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const maxRemovable = this.size - this.minSize; |
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let timeout; |
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this._removeIdleScheduled = false; |
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for (i = 0; i < available && maxRemovable > toRemove.length; i++) { |
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timeout = this._availableObjects[i].timeout; |
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if (now >= timeout) { |
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this._log('removeIdle() destroying obj - now:' + now + ' timeout:' + timeout, 'verbose'); |
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toRemove.push(this._availableObjects[i].resource); |
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} |
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} |
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toRemove.forEach(this.destroy, this); |
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available = this._availableObjects.length; |
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if (available > 0) { |
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this._log('this._availableObjects.length=' + available, 'verbose'); |
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this._scheduleRemoveIdle(); |
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} |
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else { |
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this._log('removeIdle() all objects removed', 'verbose'); |
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} |
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} |
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_scheduleRemoveIdle() { |
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if (!this._removeIdleScheduled) { |
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this._removeIdleScheduled = true; |
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this._removeIdleTimer = setTimeout(() => { |
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this._removeIdle(); |
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}, this.reapIntervalMillis); |
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} |
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} |
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_dispense() { |
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let wrappedResource = null; |
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const waitingCount = this._pendingAcquires.length; |
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this._log(`dispense() clients=${waitingCount} available=${this._availableObjects.length}`, 'info'); |
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if (waitingCount < 1) { |
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return; |
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} |
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while (this._availableObjects.length > 0) { |
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this._log('dispense() - reusing obj', 'verbose'); |
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wrappedResource = this._availableObjects[this._availableObjects.length - 1]; |
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if (!this._factory.validate(wrappedResource.resource)) { |
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this.destroy(wrappedResource.resource); |
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continue; |
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} |
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this._availableObjects.pop(); |
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this._addResourceToInUseObjects(wrappedResource.resource, wrappedResource.useCount); |
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const deferred = this._pendingAcquires.shift(); |
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return deferred.resolve(wrappedResource.resource); |
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} |
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if (this.size < this.maxSize) { |
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this._createResource(); |
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} |
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} |
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_createResource() { |
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this._count += 1; |
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this._log(`createResource() - creating obj - count=${this.size} min=${this.minSize} max=${this.maxSize}`, 'verbose'); |
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this._factory |
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.create() |
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.then((resource) => { |
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const deferred = this._pendingAcquires.shift(); |
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if (deferred) { |
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this._addResourceToInUseObjects(resource, 0); |
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deferred.resolve(resource); |
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} |
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else { |
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this._addResourceToAvailableObjects(resource, 0); |
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} |
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}) |
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.catch((error) => { |
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const deferred = this._pendingAcquires.shift(); |
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this._count -= 1; |
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if (this._count < 0) |
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this._count = 0; |
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if (deferred) { |
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deferred.reject(error); |
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} |
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process.nextTick(() => { |
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this._dispense(); |
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}); |
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}); |
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} |
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_addResourceToAvailableObjects(resource, useCount) { |
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const wrappedResource = { |
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resource: resource, |
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useCount: useCount, |
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timeout: Date.now() + this.idleTimeoutMillis, |
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}; |
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this._availableObjects.push(wrappedResource); |
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this._dispense(); |
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this._scheduleRemoveIdle(); |
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} |
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_addResourceToInUseObjects(resource, useCount) { |
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const wrappedResource = { |
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resource: resource, |
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useCount: useCount, |
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}; |
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this._inUseObjects.push(wrappedResource); |
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} |
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_ensureMinimum() { |
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let i, diff; |
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if (!this._draining && this.size < this.minSize) { |
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diff = this.minSize - this.size; |
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for (i = 0; i < diff; i++) { |
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this._createResource(); |
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} |
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} |
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} |
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acquire() { |
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if (this._draining) { |
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return Promise.reject(new Error('pool is draining and cannot accept work')); |
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} |
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const deferred = new Deferred_1.Deferred(); |
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deferred.registerTimeout(this.acquireTimeoutMillis, () => { |
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this._pendingAcquires = this._pendingAcquires.filter((pending) => pending !== deferred); |
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}); |
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this._pendingAcquires.push(deferred); |
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this._dispense(); |
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return deferred.promise(); |
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} |
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release(resource) { |
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if (this._availableObjects.some((resourceWithTimeout) => resourceWithTimeout.resource === resource)) { |
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this._log('release called twice for the same resource: ' + new Error().stack, 'error'); |
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return; |
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} |
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const index = this._inUseObjects.findIndex((wrappedResource) => wrappedResource.resource === resource); |
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if (index < 0) { |
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this._log('attempt to release an invalid resource: ' + new Error().stack, 'error'); |
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return; |
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} |
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const wrappedResource = this._inUseObjects[index]; |
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wrappedResource.useCount += 1; |
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if (wrappedResource.useCount >= this.maxUsesPerResource) { |
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this._log('release() destroying obj - useCount:' + |
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wrappedResource.useCount + |
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' maxUsesPerResource:' + |
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this.maxUsesPerResource, 'verbose'); |
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this.destroy(wrappedResource.resource); |
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this._dispense(); |
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} |
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else { |
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this._inUseObjects.splice(index, 1); |
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this._addResourceToAvailableObjects(wrappedResource.resource, wrappedResource.useCount); |
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} |
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} |
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async destroy(resource) { |
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const available = this._availableObjects.length; |
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const using = this._inUseObjects.length; |
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this._availableObjects = this._availableObjects.filter((object) => object.resource !== resource); |
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this._inUseObjects = this._inUseObjects.filter((object) => object.resource !== resource); |
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if (available === this._availableObjects.length && |
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using === this._inUseObjects.length) { |
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this._ensureMinimum(); |
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return; |
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} |
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this._count -= 1; |
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if (this._count < 0) |
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this._count = 0; |
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try { |
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await this._factory.destroy(resource); |
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} |
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finally { |
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this._ensureMinimum(); |
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if (!this._draining) { |
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process.nextTick(() => { |
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this._dispense(); |
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}); |
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} |
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} |
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} |
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drain() { |
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this._log('draining', 'info'); |
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this._draining = true; |
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const check = (callback) => { |
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if (this._pendingAcquires.length > 0) { |
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this._dispense(); |
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setTimeout(() => { |
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check(callback); |
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}, 100); |
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return; |
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} |
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if (this._availableObjects.length !== this._count) { |
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setTimeout(() => { |
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check(callback); |
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}, 100); |
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return; |
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} |
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callback(); |
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}; |
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return new Promise((resolve) => check(resolve)); |
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} |
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async destroyAllNow() { |
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this._log('force destroying all objects', 'info'); |
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this._removeIdleScheduled = false; |
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clearTimeout(this._removeIdleTimer); |
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const resources = this._availableObjects.map((resource) => resource.resource); |
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const errors = []; |
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for (const resource of resources) { |
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try { |
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await this.destroy(resource); |
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} |
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catch (ex) { |
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this._log('Error destroying resource: ' + ex.stack, 'error'); |
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errors.push(ex); |
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} |
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} |
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if (errors.length > 0) { |
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throw new AggregateError_1.AggregateError(errors); |
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} |
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} |
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} |
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exports.Pool = Pool; |
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//# sourceMappingURL=Pool.js.map
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